//part1:C05:ex5.20.cpp
// read string from input, if one string appears twice break loop.
#include <iostream>
#include <string>

int main(void) {
    using namespace std;
    string currStr, preStr;
    bool isflag = true;
    while (cin >> currStr) {
        if (currStr == preStr) {
            isflag = false;
            cout << "the repeated string is : " << currStr << endl;
            break;
        }
        preStr = currStr;
    }
    if (isflag) {
        cout << "no repeated string.\n";
    }
    
    return 0;
}
